1 variance test is conducted when you want to compare the variance or the standard deviation of the sample to conclude its population to a standard. The one variance can also be used for the baseline purposes it publishes the confidence interval of the standard deviation and variance. In the case of one variance test, the Null hypothesis states the variance of the sample is equal to standard while the Alternate will state variance is not equal to the standard. If you are checking for the standard deviation, Null will state the standard deviation of the sample equals to the standard while the Alternate will state that the standard deviation of the sample is not equal to the standard. Test of equal variance is used to check if variances of all the samples are approximately the same or they are significantly different from each other. Minitab offers Bartlett test/F test and Levene's Test to compare the variance of two different samples